Underground Boom
by bahamutOm234
Summary: Eight years ago Sonic was separated from his siblings in an explosion, both thought each other died. But now, through Sonic's medallion and guitar they know different. Eggman better be ready, because the Underground has returned. T for safety
1. Chapter 1

**I don't own Sonic the Hedgehog in anyway, shape or form.**

Sonic was wandering around a village, as Eggman was quiet, Tails was working on something, Knuckles was doing whatever, and Amy was playing volleyball with Sticks. Eventually Sonic came across a music shop, he went in hoping to find a CD but instead a guitar caught his eye as Sonic approached, he had a blurred flashback where he saw his younger self holding a guitar and two others that he barely recognized as his siblings and they had a keyboard and a drum kit. Snapping back to reality he said to himself, "I guess I haven't played guitar for a good few years... I wonder if I can still play?" Sonic bought the guitar and headed back to his house, hiding it he found Tails in his garage and said, "Hey Tails, you remember that package I gave you years ago that I told you to not open it but keep it safe until I ask for it?" Tails said, "Oh yeah, what about it?"

Taking a deep breath he said, "I'm asking for it now." Tails put his tools away and said, "Sonic? After so long I thought you would've forgotten about it. I'll go get it." Sonic said, "Thanks bud." Just then Knuckles walked by and asked, "Sonic, what's up?" Sonic said, "About eight years ago today _it_ happened." Knuckles froze, then said, "Eight years huh, you think they're okay?" Sonic said, "I'm not sure, but I bought a guitar today and maybe, just maybe they'll hear it." Knuckles chuckled, "I haven't heard you play in a long time, you sure you can still do it?" Sonic shrugged, "Who knows, but I have to try. To be honest I'm surprised no one we've met in that time noticed I always disappear on this day." Knuckles said, "Well good luck Sonic."

Knuckles then went about his business a couple minutes later Tails came back with a faded package and said, "Here it is Sonic, I've kept it safe like you wanted me to." Sonic took the package and said, "Thanks Tails." Sonic left holding the package close, Sticks asked, "What was that thing Sonic was holding?" Amy said, "I'll admit I'm a bit curious myself. Tails you mind explaining?" Tails sighed, "I'm not sure what it is, Sonic never told me." Amy was shocked, "He never told you? But you're his best friend!" Tails said, "When we first became friends he told me not to open it but keep it safe until he asked for it. I expected him to ask for it years ago but he never did, until today that is." Sticks asks, "How long have you held on to it ?" Tails said, "A long time before we met Amy, a little over seven years by now." Amy and Sticks were speechless, Tails had held on to that package for Sonic for over seven years.

Sonic had grabbed the guitar he bought and run to a high mountain, at the top he opened the package and inside was a bright medallion shaped like a double-necked guitar. Putting his hand on it he thought, ' _Sonia, Manic I miss you guys. It's been eight years since we were separated in that explosion. I hope you're both still alive, I haven't picked up a guitar since that day. Please hear me now._ ' Sonic picked up the guitar and played a few notes, then realized playing guitar was like riding a bike, you never forget how. He then played more and oddly the music seemed to echo.

Tails, Amy, and Sticks heard it and wondered where it was coming from. Knuckles smiled, thinking, 'He's still got it.' Eggman heard and thought, 'That hedgehog can still play?' Miles away a black hedgehog with red markings asked, "Who's playing that?" A bat said, "What a beautiful sound." A silver hedgehog said, "That song, it sounds familiar." A yellow rabbit stood from picking flowers and said to a chao floating nearby, "Listen Cheese, someone's playing a song." The chao, Cheese, said, "Chao, chao." And a purple cat said, "Whoever's playing that is calling out. But to what or whom?"

A pink hedgehog on the other side of the world, in Robotropolis, heard it and asked, "Could it be?" She then noticed her old keyboard medallion had a feint glow that was slowly returning it to pristine condition. She started tearing up and quickly ran to find someone. A green hedgehog also heard it and saw his old drum medallion glowing and said, "Is it really him?"

Just then the pink hedgehog ran in and said, "Manic!" The green hedgehog, Manic, said, "Sonia! Do you think it's him?" Sonia started crying, "Yes, he might still be alive!" Sonic saw his medallion glowing from the corner of his eye and said, "They can hear me!" Sonic took a deep breath and begun to sing.

' _There's something missing, something's not quite right and I can feel it calling to me every night_ '

Sonia and Manic's medallions glow brighter and Manic said, "It really is him."

Sonia sings, ' _A little voice inside tells me someone is out there and I must never give up searching everywhere!_ '

Sonic smiles as he hears them, they're alive!

Sonia and Manic: ' _Someday._ ' Sonic: ' _We are gonna be together._ '

Sonia and Manic: ' _Someday._ ' Sonic: ' _Life will be so much better._ '

Sonia and Manic: ' _Someday._ ' Sonic: ' _We will build a bond no one can break._ '

Sonia and Manic: ' _Someday._ ' Sonic: ' _No more dark clouds above._ '

Sonia and Manic: ' _Someday._ ' Sonic: ' _United in the light of love._ '

Sonia and Manic: ' _Someday._ ' Sonic: ' _The story can only end one way. We'll be together someday_.'

Sonia and Manic: ' _Someday._ ' Sonic: ' _We are gonna be together._ '

Sonia and Manic: ' _Someday._ ' Sonic: _'Life will be so much better._ '

Sonia and Manic: ' _Someday._ ' Sonic: ' _We will build a bond no one can break yeah._ '

Sonia and Manic: ' _Someday._ ' ' _No more dark clouds above._ '

Sonia and Manic: ' _Someday.'_ Sonic: ' _United in the light of love.'_

Sonia and Manic: ' _Someday.'_ Sonic: ' _The story can only end one way. We'll be together someday. Someday! be together someday!_ '

As the song ended, Sonia broke down crying, "M-manic, he-he's alive." Sonic teared up, "They're still out there." He puts his medallion around his neck and runs back to the house, guitar strapped to his back. When he gets there Tails sees him and asks, "You play guitar?" Sonic said, "Yeah, I did for a time but only today I picked it up again." Knuckles came up and said, "Any luck Sonic?" Sonic said, "Yeah. Knuckles they're alive!"

Sticks asked, "Who's alive?" Amy saw his medallion and asked, "Where'd you get that medallion?" Turning to Amy he said, "I got it from my mom when I was a baby." Then to Sticks he said, "My brother and sister are alive." Amy, Tails, and Sticks were taken aback, Sonic had siblings? Tails asked, "You have siblings?" Sonic said, "Yeah, hey you mind calling everyone together? I have some explaining to do." Tails contacted Shadow, Silver, Rouge, Cream, her chao, Cheese, and Blaze saying, "Sonic's about to explain something to all of us."

 **A/N: Okay, I've had this idea for awhile now and here it is. Anyway, to clear out some document space I'll be uploading this and the first chapters of two other fics. Next chapter Sonic will explain his royal origins.**


	2. Chapter 2

**I don't own Sonic the Hedgehog in anyway, shape or form.**

Once everyone arrived, Sonic said, "Alright, I'm not quite who you think I am. But I'm still Sonic the Hedgehog. You see I actually have a brother and sister." Blaze asked, "How come you never told us?" Sonic said, "Well, for the longest time I thought they were dead. Knuckles also knows them." Tails asked, "Wait, if that's true why did you two act like you never met?" Knuckles said, "What happened was hard on both of us." Rouge asked, "And what was it that happened?"

Sonic said, "Eight years ago in Robotropolis, my sibs and I were fighting Dr. Robotnik, or that was his name before he became Eggman, when there was an explosion, Angel Island was also caught in it, when I came to the only other person around was Knuckles and as far as I knew Sonia and Manic died. I was devastated, and angry at Robotnik. Thinking they were dead I took off my medallion and never picked up a guitar again, until today that is. Anyway after our first adventure I put the medallion in a package and asked Tails to hold onto it until I ask for it." Silver sarcastically asked, "Is there anything else you neglected to tell us hm? Like you're a prince or something?"

Sonic and Knuckles shared a look, then Sonic said, "Well since I did tell you about my siblings... I am in fact a prince. My mother was Queen Aleena, I am Prince Sonic, my brother is Prince Manic, and my sister is Princess Sonia. I never said anything because it was painful to recall and I didn't want to be treated differently." Everyone was shocked, Cream asked, "How did you first meet your siblings?" Sonic smiled, "Music." Amy asked, "Wait, music? How'd that bring you together?" Sonic said, "To understand that you'll need to know the story, get comfortable cause it's a long one." Once everyone was situated Sonic began, "When we were born Robotnik attacked Mobotropolis, my mom escaped with us and met an old oracle who prophesied that one day we'll be reunited and overthrow Robotnik. Unfortunately there was a cost, she had to separate us from her and each other while she lied in wait. Sonia was taken to an aristocrat, Manic was supposed to end up with a family in the city but was instead taken in and trained to be a thief."

Cream interrupted, "What about you Sonic?" Sonic continued, "I was taken to the countryside to live, unfortunately the family I stayed with was taken so I went to live with Uncle Chuck and joined the Freedom Fighters. See Eggman had put up in a shield around one of his factories, Unc had me blast through and destroy it but I was left exhausted then the Oracle showed up and said my destiny awaits, being as exhausted as I was I said 'Yeah, yeah tell it to wait outside I'm too tired to care.'"

Knuckles, Silver, and Tails laughed while Shadow snickered and the girls giggled Sonic continued, "After the Oracle gave me some energy he told me of my status as Prince and of my sibs then said, 'To find them you must sing the song from your heart.' I was confused for a minute then figured out what he meant. I then started to play 'Someday' like I sung a few minutes ago then I heard Sonia and Manic sing as well, realizing they were out there I went to a club the resistance put together and started playing soon I was joined by Manic and Sonia. Later we began our journey as Uncle Chuck, Lady Windamir, the aristocrat that took Sonia in, and Ferall the one who took Manic in and taught him thievery were robotisized by Ol' Buttnik, as I used to call him."

He then launched into an explanation of their adventures up until the separation. Sonia and Manic rushed to the resistance HQ and Manic shouted, "Yo! Cyrus! You there?" A lion, Cyrus came out and said, "Manic? What is it?" He then saw Sonia crying again and also saw she was wearing her medallion and asked, "You guys came back to fight?"

Manic said, "I'll explain everything to everyone." Cyrus gathered the resistance and Manic said, "Alright as you all know, eight years ago Sonia and I stopped fighting because Sonic wasn't around. But that's about to change. Sonia spoke up, "We all thought Sonic died in that explosion but now we know different, he's alive." The resistance was shocked and happy, Manic continued, "Our medallions started glowing again after so long and we know Sonic was reaching out to us, Sonia and I are going to find him. Then we might be able to take back Mobotropolis!" The crowd cheered, Cyrus then asked, "How will you track him?" Sonia smirked, "The same way we found out he was alive." Cyrus then realized, "The medallions!" They then started heading in the direction of Sonic and his friends.

Sonic's ears prick and his medallion glows, smiling he said, "They're coming." Noticing Amy starting to freak out he asked, "You okay Ames?" Amy said, "What if they don't like me?" Sonic and Knuckled started chuckling then erupted in laughter, Sticks looked at Tails confused and he just shrugged while Amy pouted, Sonic said, "C'mon Amy, everyone who's met ya liked ya. Except Egghead, but he's Eggman so that doesn't matter." Knuckles then said, "Ya know Amy, back then the girls in the resistance were always after Sonic. I remember one, Sally I think her name was, that almost became his girlfriend but it didn't work out and he turned down everyone else. Tails and I know Sonic and rest assured he'll stick by you."

Tails suddenly asked, "Wait, am I a prince now to?" Sonic said, "I did adopt you as my younger brother didn't I? So yeah I think you're now Prince Tails." Rouge's eyes glinted at the thought of the treasure he might have, seeing it Sonic said, "I'm sorry Rouge, but as far as my sibs and I know Eggman already took all the royal family's treasure." Turning to Amy, he said, "So Amy, how'd ya like to become a princess?"


	3. Chapter 3

**I don't own Sonic the Hedgehog in anyway, shape or form.**

Amy said, "I'd love to be a princess!" Sonic said, "Cool, when the time comes you'll be a princess. Although you already are mine." Amy blushed, and Sonic said, "Alright, they're going to be using the medallions to find me." Sonic summoned his guitar and started playing. Meanwhile in the Sonic Underground Van, Cyrus set up a scanner attuned to the medallions and said, "Alright Sonia, Manic, the scanner is set up. And I packed enough fuel in case of a long journey. Good luck." Sonia took the wheel and said, "Thanks Cyrus, we'll be back as soon as we can."

Driving out of Robotropolis undercover of night, they picked up a very faded trace of Sonic at the Green Hill Zone, hopping out Sonia asked a villager if they had seen a blue hedgehog, the villager said, "Oh yeah, a little less then eight years ago. Why?" Sonia said, "He's our older brother, and we were separated eight years ago today." The villager said, "Ah, well after helping us he left for the Knothole forest, maybe he's still there."

Sonia thanked him and said to Manic, "Sonic's not here but was then headed to the Knothole Forest." Manic nodded and headed there, getting there in four hours thanks to the upgrades, Manic saw a partially Robotisized rabbit and said, "I take it Robotnik passed through here." The rabbit said, "Sure did sugah, names Bunnie Rabbot." Manic said, "I'm Manic Hedgehog, my sis Sonia is sleeping in the van." Bunnie said, "Hedgehog eh? Kinda like Sonic then." Manic said, "Yeah, he's my brother." Bunnie said, "Huh, you, your sister and him had the same mother then." Manic said, "Right, you seen him recently?"

Bunnie shook her head, "Nah sorry shug, he and the fox he adopted as a little brother left for Station Square about five years ago." Thanking her he climbed back in the van as Sonia woke up and said, "Sonic was here five years ago then went to station square with a fox he adopted as a little brother." Sonia nodded and they drove off again.

Meanwhile, Sonic had sent Eggman back to his lair before playing his guitar some more, Blaze asked him, "Did you and your siblings play many songs?" Putting his guitar down, Sonic said, "Oh yeah, about forty. You probably heard me sing Someday earlier, that was the first song we wrote." Cream asked, "What were your other songs called?" Knuckles said, "I remember four songs, Not Always What They Seem, No One is An Island, Learn To Overcome, and The Mobius Stomp." Sonic said, "After Someday we wrote Working Together In Harmony, and We're All In This Together."

Once Sonia and Manic reached Station Square, they were surprised to see more humans than Robotnik and asked, "Have you seen a blue headgehog named Sonic recently?" Someone said, "Oh yeah, about two years ago. After he drove Eggman out of town he headed to a place simply called 'The Village'." Sonia asked, "Eggman?" The person said, "Yeah, he was a bald guy with a crazy mustache with robots that always caused trouble." In the van, Manic said, "Seems like Robotnik changed his name to Eggman. Sonia said, "Seems like, so after the explosion Sonic has been fighting Eggman while we haven't done anything." Manic said, "I guess we were too upset to focus while Sonic directed his time to fighting Eggman. C'mon sis, we're heading to The Village."

Rouge asked, "What can you tell us about your siblings Sonic?" Sonic said, "Well, I don't know if anything has changed. Sonia was easily the strongest of us and the most acrobatic, plus she knew how to debate. Luckily during our adventures she mellowed out from being snooty, and became more willing to get dirty. Manic, I'm sure you'd like because he was quite the thief Tails would also like him, because Manic was the best hacker I knew before I met Tails." In the village Sonia and Manic pulled up and asked an eagle where Sonic was, Soar said, "He's probably at his beach house on the other side of the forest." Sonic turned toward the forest and said to his friends, "Here they come."

Looking toward the forest, they saw a van burst forth from the forest and skid to a stop, Sonic then said aloud, "Gang, meet my siblings, sibs meet the gang." Sonia and Manic tackled Sonic and Sonia said, "Sonic it's so great to see you again!" Knuckles said, "H-hey Sonia. It's me Knuckles." Sonia let go and said, "Knuckles, how've you been?" Knuckles said, "I've been good, a few years back I started helping Sonic fight Eggman." Manic said, "So, who're they?" Sonic said, "The fox is Miles, everyone just calls him Tails though." Tails said, "Hi, I'm Tails. Sonic helped me get some confidence." Sonia said, "I'm Sonia, this is Manic. A Rabbit said Sonic adopted you as a little brother." Tails said, "Oh, must've been Bunnie. I'm still trying to figure out away to reverse being robotisized."

Knuckles said, "The pink headgehog is Amy Rose." Amy shyly said, "Um hi." Sonic said, "Amy here's my girlfriend, it took a few years but she mellowed out from being obsessive." Bolstered by Sonic being next to her she said," Yeah, I started crushing on Sonic after he saved me and started chasing him down. I soon realized I needed to calm down if I didn't want Sonic to bolt the moment he saw me." Tails said, "Once she calmed down they started hanging out more and more eventually dating."

Silver came up and said, "I'm Silver, I was originally from the future and was lied to saying as long as Sonic lives the future would remain a wasteland. I eventually found the truth and opted to stay in this time." Rouge said, "I'm Rouge, a treasure hunter and a part time agent for GUN." Manic said, "Sonic probably told you I'm a thief, so I'm sure we'll get along." Shadow said, "Name's Shadow, over forty years ago I was created by Eggman's great grandfather as a friend for his crippled daughter Maria. Unfortunately she died, as I was trying to save her I was put in a coma and sealed away. A few years back Eggman released me to end Sonic and, regrettably I went along for a time. Eventually Sonic convinced me Eggman was the enemy." Cream relapsed into her old manner of speaking, "Hello Mr. Manic and Ms. Sonia, my name's Cream and this is my Chao, Cheese." Amy said, "Cream, it's all right you don't need to be nervous." Sonic said, "Cream used to be extremely timid, now she only acts like that when she's nervous."

Blaze said, "I'm Blaze, similar to Silver, I'm not originally from this dimension rather than from the future. I was from what I suppose could be considered a mirror dimension where Eggman is actually competent. I was the guardian of seven powerful gems called Sol Emeralds, think of them as mirror versions of the Chaos Emeralds." Sonia asked, "Chaos Emeralds? I thought there was only one?" Knuckles said, "Well no, the emerald you helped me reclaim from Sleet and Dingo was the Master Emerald, course back then it was just a big emerald. By the time that explosion happened the Emerald had reached full size and the seven chaos emeralds were created." Sonic then said, "The badger is Sticks, she's... Out there."

Sticks said, "Out where? Where are you saying I am?" Sonic said, "See. She's also a bit paranoid." Tail's said, "Yeah, she once accused one of my robots of being in her head. I originally designed it to translate any language into our own, but then it started translating what we said into what we meant. Looking back I'm glad Sticks' paranoia caused her to throw it in the ocean." Manic asked, "Why?" Tails responded, "Well it was before Sonic and Amy got together and it almost revealed she was in love with him." Sonic said, "Why don't we head inside, there's a lot to catch up on."


End file.
